What is ocean acidification? Why should I care about it?

Transcription

1 What is ocean acidification? Why should I care about it? Shallin Busch, Ph.D. Northwest Fisheries Science Center National Oceanic and Atmospheric Administration

2 Outline of talk 1) A cartoon 2) The ocean interacts with the atmosphere 3) Ocean chemistry 1) How it works 2) Future projections 4) Water chemistry affects species 5) Ecological communities 6) What to do about acidification?

3 Hermie the Hermit Crab

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6 Carbon Dioxide and Seawater Carbon dioxide atmospheric Carbon dioxide in water CO 2(atmos) CO 2(aq) + H 2 O

7 Carbon Dioxide and Seawater Carbon dioxide atmospheric Carbon dioxide in water Ocean Acidification - The Basic Equation CO H 2 CO 3 H + + HCO - 3 2H + + CO 2-2(atmos) CO 2(aq) + H 2 O 3

8 What is acidity? What is ph? Acidity is a measure of H + ( H +, ph) ph is the scale used to measure how acidic or how basic something is

9 What is acidity? What is ph? Acidity is a measure of H + ph is the scale used to measure how acidic or how basic something is ph is measured on the log scale Change in 0.1 ph unit is a 30% increase in H +

10 What is acidity? What is ph? The ph scale was developed by Prof Sørensen at the Carlsberg brewery in 1909.

11 Ocean acidification is a decline in ocean ph due to increased atmospheric CO 2

12 Has acidification already occurred? CO 2(atmos) CO 2(aq) + H 2 O H 2 CO 3 H + + HCO 3-2H + + CO 3 2-

13 Has acidification already occurred?

14 ph will decline with CO 2 emissions

15 Scientists predict a % increase in ocean acidity by the year 2100.

16 This change is really quick! NOAA Earth History Research Lab:

17 Pelejero et al., 2010 This change is really quick!

18 When CO 2 in the atmosphere 1. CO 2 in the ocean increases & ph increases 2. CO 2 in the ocean increases and ph decreases 3. CO 2 in the ocean decreases & ph increases 4. CO 2 in the ocean decreases & ph decreases increases:

19 Which is false? 1. Ocean ph has never been as low as it is now. 2. Ocean ph has never dropped as quickly as it is currently. 3. Quick changes in ocean ph are linked with mass extinction of marine species. 4. Ocean ph affects species that live on the surface of the water and at depth.

20 Why does ocean acidification matter to marine organisms? Ocean Acidification - The Basic Equation CO H 2 CO 3 H + + HCO - 3 2H + + CO 2-2(atmos) CO 2(aq) + H 2 O 3

21 Gas exchange is affected by OA

22 Gas exchange is affected by OA

23 Sensory tissues are affected by OA

24 Development is affected by OA

25 Sea Urchin Life Cycle 2-armed planktonic larva Cleavage adult juvenile Many-armed planktonic larva Impacts of ocean acidification on an individual can be large during the organizational activities that occur during development.

26 Shells are affected by OA

27 Shells are Calcium Carbonate Calcium carbonate Carbonate + Calcium CaCO 3 CO Ca 2+

28 Shells are Calcium Carbonate Calcium carbonate Carbonate + Calcium CaCO 3 CO Ca 2+ Ocean Acidification - The Basic Equation CO 2(atmos) CO 2(aq) + H 2 O H 2 CO 3 H + + HCO 3-2H + + CO 3 2-

29 Cohen et al Shells may be harder to build

30 Shells may be harder to build Calcium carbonate Carbonate + Calcium CaCO 3 CO Ca 2+ Ocean Acidification - The Basic Equation CO 2(atmos) CO 2(aq) + H 2 O H 2 CO 3 H + + HCO 3-2H + + CO 3 2- Cohen et al. 2009

31 Shells may dissolve Green et al Busch et al., unpublished

32 Shells may dissolve Calcium carbonate Carbonate + Calcium CaCO 3 CO Ca 2+ Ocean Acidification - The Basic Equation CO 2(atmos) CO 2(aq) + H 2 O H 2 CO 3 H + + HCO 3-2H + + CO 3 2-

33 What is Calcium Carbonate? Holcomb et al. 2010

34 About 600 non-vertebrate species in Puget Sound produce CaCO 3

35 Response of 2 oyster species is different Miller et al 2009

36 Responses to OA can be unclear

37 Public s questions about OA? 1) How will OA affect : my hatchery? my fishery? tourism in my area? conservation efforts in my area? an ecosystem I care about? 2) Is OA the biggest climate change problem for the marine environment? 3) Will OA cause similar changes to ecological communities everywhere?

38 West Coast Oyster Failure Willapa Bay: Wild oysters have had low levels of reproduction over the last 7 years Hatcheries: Production of larvae reduced over last 6 years Correlations of failure with ph?

39 Species are connected in food webs

40 Puget Sound Ecosystem

41 Forage fish Sea lions Harbor seals Migratory diving birds Resident diving birds Nearshore diving birds Herbivorous birds % change in biomass Gulls Raptors Impacts on Puget Sound? Combined Non-cephalopod molluscs Echinoderms Crustaceans

42 Culture?

43 Harvest from the Sea?

44 What can we do??

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46 Reduce Other Stressors

47 Plan for Change

48 We have much to learn! 1) We are just starting to understand the impacts of ocean acidification 2) There will be species that respond negatively, positively, and not at all 3) Acidification has been linked with mass extinction in the past, so we are worried

49 Acid Test Movie